Washington: Hurricane Sandy, one of the worst storms to hit US in decades, has plunged the final week of electioneering into chaos, with President Barack Obama and his Republican rival Mitt Romney cancelling and rescheduling their rallies in critical battleground states.

Given the seriousness of the hurricane, Obama suspended his election campaign mid-way and returned to the White House to personally review the preparedness.

Romney, 65, also had to cancel his election meetings in the storm affected areas.

Both Obama and Romney cancelled events in Virginia.

Romney also cancelled his New Hampshire trip, but would continue with his campaign in the battleground states of Ohio, Iowa and Wisconsin which are away from the storm.

"The top priority is the safety and security of people who may be in harm`s way," senior Romney campaign adviser Kevin Madden said yesterday.

"So we`ll have to monitor the storm and make sure that we see if we need to make any adjustments but it`s hard to predict at this point," Madden was quoted by Fox News as saying.

The campaign also has stopped sending fundraiser emails in New Jersey, North Carolina, Pennsylvania, Virginia and the District of Columbia -- all expected to be hit by the storm`s high winds and heavy rains.

The storm is expected to make a landfall later today, ahead of the November 6 election, as Romney and Obama frantically tried to close the deal with voters in a race that is essentially too close to call.

Strategists suggested that the Democrat campaign stood to be worst affected by the hurricane since it could reduce the traditional Democrat advantage with early voters in swing states such as North Carolina, Virginia and New Hampshire.

Obama also has to juggle the responsibilities of being commander in chief and leading his re-election campaign.

Yesterday, the president visited the Federal Emergency Management Headquarters, as the agency begins to help with state- and local-level preparedness efforts.

"Anything they need, we will be there," said the president, attempting to demonstrate steady leadership in the face of crisis and knowing an ineffective administration response could hurt his presidency and re-election efforts.

Virginia Senator Mark Warner was quoted by the channel as saying ,"the storm will throw havoc into the race, but the president will carry the state."

"Obviously, we want unfettered access to the polls, because we think the more people that come out, the better we`re going to do," said David Axelrod, a top adviser to Obama`s campaign. "To the extent that it makes it harder, that`s a source of concern."

The massive storm is churning up the US Atlantic coast nine days before voting in the extremely close race for the White House.